The name Thames comes from the Celtic name of the river – Tamesas, though the Romans thought it was her, they discovered and named. In the era of the Roman conquest legions repeatedly reached Britain. His second military campaign in Britain, Julius Caesar made in 56 BC, but progress beyond it prevented the river, which he named Tamesis (Thamesis). To conquer the Britons, the Romans were only able to in 90 years during the reign of Claudius. The Romans built cities and roads and then left, and the Britons were called and the river of the same name – Thames.